ADAPTLOAD: effective balancing in clustered web servers under transient load conditions

We focus on adaptive policies for load balancing in clustered web servers, based on the size distribution of the requested documents. The proposed scheduling policy, ADAPTLOAD, adapts its balancing parameters on-the-fly, according to changes in the behavior of the customer population such as fluctuations in the intensity of arrivals or document popularity. Detailed performance comparisons via simulation using traces from the 1998 World Cup show that ADAPTLOAD is robust as it consistently outperforms traditional load balancing policies, especially under conditions of transient overload.